Conventional techniques for determining tire quality, such as whether tread of a vehicle tire is sufficient or is too worn, include evaluating the tread using an object such as a penny and determining how much of the penny is obscured by the tread. Such techniques are prone to errors in determining whether enough of the penny is obscured by the tread. Some such errors may result from not accounting for the fact that different amounts of tread are considered sufficient for different types of tires. Conventional techniques for determining tire quality have various other drawbacks as well.